Re: [PATCH V2] iommu/arm-smmu: add actlr settings for mdss on sa8775p platform

From: Dmitry Baryshkov

Date: Tue Nov 18 2025 - 13:04:06 EST


On Tue, Nov 18, 2025 at 10:48:22PM +0530, Charan Teja Kalla wrote:
> Add ACTLR settings for the mdss device on Qualcomm SA8775P platform.
> This is achieved by adding compatibility string for mdss in the actlr
> client of match table.
>
> Signed-off-by: Charan Teja Kalla <charan.kalla@xxxxxxxxxxxxxxxx>
> ---
>
> Changed from V1:
> 1) Added actlr setting only for MDSS and dropped for fastrpc. -- konrad
> 2) ACTLR table is updated per alphanumeric order -- konrad
> https://lore.kernel.org/all/20251105075307.1658329-1-charan.kalla@xxxxxxxxxxxxxxxx/
>
> drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> index 62874b18f645..0b400e22cb00 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> @@ -41,6 +41,8 @@ static const struct of_device_id qcom_smmu_actlr_client_of_match[] = {
> .data = (const void *) (PREFETCH_DEEP | CPRE | CMTLB) },
> { .compatible = "qcom,fastrpc",
> .data = (const void *) (PREFETCH_DEEP | CPRE | CMTLB) },
> + { .compatible = "qcom,sa8775p-mdss",
> + .data = (const void *) (PREFETCH_DEFAULT | CMTLB) },

What's the difference from SC7280? Why don't we need to set CPRE?

> { .compatible = "qcom,sc7280-mdss",
> .data = (const void *) (PREFETCH_SHALLOW | CPRE | CMTLB) },
> { .compatible = "qcom,sc7280-venus",
> --
> 2.34.1
>

--
With best wishes
Dmitry